Unfortunately, there is no officially supported or widely-used programming language called “RPL” that fits your request. There is, however, a scripting language for TI-Calculators called “TI-BASIC” which includes a command very similar to “Hello World”. The equivalent of “Hello World!” in RPL (which stands for Reverse Polish Language) is not straightforward because it’s primarily a reverse polish notation mathematical calculation system and doesn’t directly support strings.
RPL is used on HP Prime Calculators (a successor to HP-41C). However, as per your requirements, here’s an example of a “Hello World!” program in TI-BASIC, which can be found in the TI 8x and 9x series graphing calculators.
TI-Basic
Disp "Hello World!"
Text model: dolphin-mistral
Image model: JuggernautXL
